Summary The 15th Annual Meeting of the International Cytokine Society (ICS) will be held in San Francisco, California from October 26-30, 2007. This international conference, titled "Cytokines in Health and Disease," will bring together leading investigators in the fields of cytokine signaling and biology, immunology, cancer research, and infectious diseases. The meeting is organized by Drs. Stephen Smale, Richard Flavell, Laurie Glimcher, Christopher Hunter, and Abul Abbas, who study cytokines from a broad range of perspectives. A major goal of the meeting will be to promote interactions between scientists performing cutting-edge studies of the molecular mechanisms of cytokine function, signal transduction, and gene expression, and those working to translate this knowledge into novel therapies for human disease. The therapeutic potential of cytokines and of modulators of cytokine signaling and expression are now appreciated, raising the need for enhanced interactions between basic, translational, and clinical researchers in this exciting field. In addition to approximately 48 invited speakers scheduled for Plenary Sessions and Symposia, a number of abstracts submitted by registrants will be selected for oral presentations in Special Topics Sessions, with other registrants given the opportunity to discuss their work at poster sessions. Scientists from academic institutions as well as from the biotechnology and pharmaceutical industries have been invited and encouraged to participate. Outstanding junior investigators, postdoctoral researchers, and graduate/medical students will also be encouraged to participate, and awards will be given to three or four young researchers in each of these categories. A special effort will be made to support the career development of under-represented minorities and women. Although our overriding objective is to bring together researchers studying cytokines from diverse perspectives, one major theme of the meeting will be recent studies of the emerging field of T helper 17 (Th17) cell development and functions in normal physiology and a variety of diseases, with one Plenary Session devoted entirely to this important and exciting new research area. The titles of other Plenary Sessions and Symposia are "Innate Immune Recognition and Responses," "T-Cell Subsets," "Cytokines, Chemokines, and Inflammation," "Inhibitory Receptors and Cytokines," "Gene Regulation," "Inflammation and Cancer," "Signal Transduction," "Regulation of Macrophage Activities and Functions," and "Clinical Progress." It is the firm belief of the Organizing Committee and ICS Leadership that, by bringing together leaders, junior investigators, and trainees in these diverse areas of cytokine research, this meeting will inspire important new avenues of investigation and will be of great benefit to the career development of promising young investigators and trainees in the cytokine field.